Conventional lighting systems allow a user to define colors for lighting fixtures one fixture at a time. If the user wants to display an array of colors, such as the colors in a rainbow, across the lighting fixtures, then the user must define each color that will be displayed and assign each lighting fixture one of the defined colors. Depending upon the number of lighting fixtures and the colors that the user selects, the process can be fairly tedious. In the case of an array that follows a known color order, such as a rainbow, it would be simpler if the user could define a starting color and an ending color and have the lighting controller determine the intermediate colors and determine which colors to assign to which fixtures.